A fluoropolymer containing repeating units having a fluorinated alicyclic structure in its main chain is excellent in physical properties such as optical characteristics (such as transparency and durable light resistance) and water and oil repellency.
As a cyclic polymerizable compound which forms the above repeating units, a polyfluoroalkenyl vinyl ether such as CF2═CFOCF2CF2CF═CF2 has been known (e.g. Patent Document 1).
Further, a fluoropolymer containing repeating units having a fluorinated alicyclic structure in its main chain and having a functional group is excellent in the above physical properties and in addition, physical properties derived from the above functional group can be developed, and such a polymer is applied to various fields (e.g. a resist material for lithography) (e.g. Patent Document 2).
As a cyclic polymerizable compound which forms the above repeating units, Patent Document 2 discloses a fluoroalkadiene having a functional group (such as CF2═CFCF2C(CF3)(OH)CH2CH═CH2).
Further, as a fluoroalkadiene having a group analogues to a carboxyl group, Patent Document 3 discloses 1,1,2-trifluoro-4-alkoxycarbonyl-1,6-heptadiene (CF2═CFCH2CH(C(O)OC(CH3)3)CH2CH═CH2 or the like).
Patent Document 1: JP-A-01-131215
Patent Document 2: WO02/064648
Patent Document 3: JP-A-2005-298707